The wax we us is Meguiars Mirror Glaze No.8

What direction are you laying up your glass? I would suspect you are running the weave at a 45° from the mold, this will give you the torional strength and keep the wing from twisting.

Well, the engineer I work with wants me, after I make some Nomex honeycomb wings, to use 1/16" balsa as the core material, but that sounds thin to me on a 35% wing that will be taking some massive amount of G's. But he has done the math and assures me that it will work. (It's not his $1000 engine if it fails)

I would stick with the 1/16" and would use 5-7lb contest balsa, because you might run into problems with not enough skin thickness for buckling strength if you use a thinner material.

Main thing I would do at this point is to figure out a way to seal the balsa, especially the endgrain balsa. Balsa absorbs in the direction of it's grain so a light resin layup will have the possibility of having the resin sucked up by the balsa and leaving dry spots in the glass.


What do you use to close up the molds? what type of material?

Do you mean once the halves are bolted? I run 1" glass tape saturated in a epoxy/microballon mix.

I have made my molds like you have, simply because I do not have any of the tooling resins, I would like to try them in the future.

One trick I have learned is after you lay down a couple of layers of glass, mix dry sand or sawdust, 8 parts to 1 part epoxy and spread out a 3/8" layer of this slurry, then put the same amount of glass layers on top. Just a cheap and easy way to build thickness. If it is a large part, lay cut pieces of conduit in the slurry then glass over them, this keeps the mold from twisting and adds strength.


If you look in the aerodynamics/scratch build section, Ollie and several others have made molds and can offer other ideas too. We are all learning so no one has all the answers.

Regards,

Darrin C